1. Field of the Invention
The invention relates to signs used for vehicle traffic control on public roads.
2. Description of the Prior Art
Various known, standard traffic signs are disclosed in the “Manual on Uniform Traffic Control Devices for Streets and Highways,” 2003 edition with Revision 1 dated November 2004 and Revision 2 dated December 2007, published by the U.S. Department of Transportation under the Federal Highway Administration. The Manual places known highway signs in three categories. These categories are regulatory signs, warning signs and guide signs. Regulatory signs inform drivers of traffic laws and regulations. Warning signs warn drivers of traffic of unusual or potentially hazardous conditions on or adjacent a street or highway. Guide signs give the driver simple and specific information to aid the driver in reaching a destination. In all categories and particularly in the regulatory and warning categories, the signs convey only one traffic message. No secondary traffic message or information is imparted by the signs.
The stop sign is a mostly uniform regulatory traffic sign in use throughout the United States. An example of a standard stop sign 1 with is illustrated in FIG. 6. Standard stop sign 1 is typically a red octagon with a white legend 3 and border 7. The word STOP in white letters is the legend 3 and it is in the middle portion 2 of the sign 1. The signs are placed at traffic intersections to require motorists to stop before entering the intersection. Its purpose is to give the motorist time to examine the intersection for interfering traffic before passing through. Stop signs are typically placed and used to increase safety.
However, there are shortcomings to using a single type of stop sign for all type of intersections. With the standard stop sign, it is difficult, if not impossible, for a driver to determine from the sign if there is any particular secondary traffic situation nearby that may present a danger. Some intersections have four-way stops, some have more, and some have fewer. There are intersections at which not all of the inlets have stop signs, and particular inlets have a right of way. A driver cannot tell this until the driver reaches the intersection who might have the right-of-way. This can cause driver confusion and therefore accidents.
One solution that has been used most often has been to add a small tag below the octagon stating the number of directions having a stop sign. They usually say “2-WAY”, “3-WAY”, or “4-WAY” to indicate the number of directions that have to stop. FIG. 6 also illustrates such a typical secondary legend 6. While that is an improvement, there is a great probability that a viewer in a moving vehicle will not notice it in time to take action. It is well known that drivers receive information faster if it is graphical as opposed to only text. Examples of such graphical information are the signs containing a “U” with a superimposed circle with a diagonal line to indicate no “U” turn permitted. The symbol conveys the same information and is comprehended more quickly by a driver than the words “No U-turn”. This is especially so for someone who has difficulty reading English.
Various other types of stop signs have been disclosed. U.S. Pat. No. D399,260 (1998, Thimote) discloses a traffic sign system. It is a design patent and the drawings disclose an octagon shaped sign with a border and a legend in the lower half of the sign and one or more arrows in the upper half of the sign. The purpose of the right and left arrows on the stop sign is not described. Thimote teaches a stop sign that has a left arrow, a right arrow, and a left and right arrow, and nothing else. The meaning of each embodiment is ambiguous, since it could mean either that a driver could go towards that direction, or to look out for traffic from that direction.
U.S. Pat. No. 6,519,884 (2004, Duhamel) discloses a street and road sign. Duhamel teaches the use of secondary traffic symbols placed within the primary stop sign to generally indicate which inlets at the intersection have stop signs. While this is an improvement over the prior art, this stop sign cannot property indicate the status of an inlet that is at some orientation to the intersection other than 0, 90, or 270 degrees from the viewer. There is insufficient room within the boundaries of the octagonal stop sign to accurately and clearly represent other orientations. Furthermore, unless all stop signs in the country are changed simultaneously, a viewer of an older stop sign without any secondary stop signs would be forced to assume that each intersection inlet would have the right of way over the viewer. This would be a disadvantage.
Therefore, what is needed is an informational stop sign that graphically and accurately shows the position and right-of-way status of each inlet to an intersection.